Textile fiber processing elements



y 1961 J. ROCKOFF 2,991,515

TEXTILE FIBER PROCESSING ELEMENTS Filed Sept. 16, 1957 JOS P ROQKO: F

I VENTOR ArToRNev United States Patent 2,991,515 TEXTILE FIBER PROCESSING ELEMENTS Joseph Rockolf, Dayton, Ohio, assignor to Dayco Corporation, a corporation of Ohio Filed Sept. 16, 1957, Ser. No. 684,110 5 Claims. (Cl. 19-143) This invention relates to textile fiber processing elements. It relates more particularly to such elements having an improved sur-face composition and has particular application to spinning rolls, roll covers or cots, drafting aprons, rub aprons, and similar elements such as are utilized in the drawing or condensing of cotton, rayon, wool and other textile fibers.

Textile fiber processing elements of the type described have in the past been formed with at least the working surfaces thereof composed of a synthetic rubber-like material of the acrylic nitrile-butadiene copolymer type. As described in U.S. Patent No. 2,304,656 to Rockoif, it was found that textile machine elements of this type having surfaces which incorporated as an essential constituent thereof a synthetic rubber of this type would provide products having increased resistance to eyebrowing and lapping. These products would also at the same time have a high degree of oil resistance as well as good wearing qualities. Although products incorporating synthetic rubber-like materials of this type are now almost universally used in the processing of textile fibers, and the use of this material has been unusually satisfactory by comparison with the materials previously available in the prior art, one of the disadvantages of this material has proven to be its tendency to acquire a surface glaze during use. This glazing results in the impairment of the functioning of the articles in question, and in the case of textile machine elements of the type described has been found to hinder their normal functioning in the handling of textile fibers, so that their drafting or condensing abilities are impaired.

In accordance with the present invention, applicant has discovered that glazing of the surfaces of these products composed of acrylic nitrile-butadiene copolymers, and the like, may be minimized or prevented by incorporating into the rubber compound a small proportion of nickel dibutyl dithiocarbamate. The incorporation of this chemical material in a preferred proportion of about 2 to 8 parts per 100 parts of rubber hydrocarbon, in otherwise conventional compositions of this type, has been found to be highly effective in thus reducing or preventing glazing in use. Conventional rubber compounding materials, such as sulfur, accelerators, vulcanizing agents, antioxidants, fillers, and the like, may be incorporated in the usual manner.

The invention will be more fully understood from the following description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a view in elevation of a typical drafting roll or cot.

FIGURE 2 is a view in elevation of a typical fiber drafting apron.

FIGURE 3 is a view in elevation of a typical textile rub apron.

Referring to the drawings, the cot construction 10 of FIGURE 1 is formed with roll covering elements 11 and 11a mounted upon core 12. The cot is formed in a conventional manner; for example, as described in Rockoif U.S. Patent No. 2,304,656, referred to above. A typical cot composition is as follows (parts by weight):

Acrylic nitrile-butadiene copolymer (35% acrylic nitrile65% butadiene) 100 Zinc oxide 10 Clay 50 Accelerator (benzothiazyl disulfide) l 'ice The above ingredients are milled together, extruded, and vulcanized to form cots in the manner described in the above-mentioned patent to Rockoif. When utilized as cots in the drafting of cotton and rayon fibers, compositions of the above type have been found to function effectively over periods of many months without glazing. On the other hand, when the nickel dithiocarbamate is omitted, the cots will develop a glaze within a few weeks. Similar results are obtained with other cot compounds based upon acrylic nitrile-butadiene copolymers. For example, white factice containing cots of the type described in Rockofl U.S. Patent No. 2,671,- 249 also exhibit similar improvement in non-glazing properites by the incorporation of nickel dibutyl dithiocarbamate. The same type of improved results are observed in connection with the cots described in Rockotf U.S. Patent No. 2,763,033, and, in general, with butadiene-acrylic nitrile compositions. Other proportions of the nickel dibutyl dithiocarbamate have been found effective; however, less than 2 parts per parts of ru-bber hydrocarbon begins to show a loss of effectiveness, whereas more than 8 parts per 100 appears to offer no additional advantage and may be considered unnecessary.

The long draft apron shown in FIGURE 2 is also provided with a surface layer 13 composed of a butadiene-acrylic nitrile copolymer containing nickel dibutyl dithiocarbamate. A compound of the type described above, as used for cots, is also utilized in forming the drafting surface of aprons; for example, of the type shown in the U.S. patent to Bacon 'et al. No. 2,484,810. Such aprons are found to be relatively free from glazing over long periods of use, whereas in the absence of the novel ingredient referred to, glazing may take place in a much shorter period of time.

FIGURE 3 ilustrates a rub apron of the type shown in the U.S. patent to Bacon et al. No. 2,621,375. When nickel dibutyl dithiocarbamate is incorporated in the surface composition of such aprons which are based on butadiene-acrylic nitrile copolymers, it is found that the tendency to glaze during use, otherwise encountered in the absence of the material, is almost completely eliminated.

It will be understood that while the foregoing invention has been illustrated with reference to cots, aprons, and rub aprons, it may be applied, in general, to textile fiber processing elements having working surfaces comprising butadiene-acrylic nitrile copolymers and Wherever glazing may occur through contact of textile fibers with such surfaces.

I claim:

1. A textile fiber processing element having a working surface comprising a vulcanized butadiene-acrylic nitrile copolymer having a minimum of two parts by weight of nickel dibutyl dithiocarbamatae per 100 parts by weight of the copolymer incorporated therein, whereby glazing of said working surface is prevented.

2. A textile fiber processing element having a working surface comprising a vulcanized butadiene-acrylic nitrile copolymer having about two to eight parts by weight of nickel dibutyl dithiocarbamate per 100 parts by weight of the copolymer incorporated therein, whereby glazing of said working surface is prevented.

3. A textile cot having a working surface comprising.

a vulcanized butadiene-acrylic nitrile copolymer having about two to eight parts by weight of nickel dibutyl dithiocarbamate per 100 parts by weight of the copolymer incorporated therein, whereby glazing of said working surface is prevented.

vulcanized butadiene-acrylio nitrile copolymers, which iny eludes incorporating into such surfaces prior to the vulcanization thereof a minimum of two parts by weight of nickel dibutyl dithiocarbamate per 100 parts by weight of the copolymer.

References Cited in the file of this patent UNITED STATES PATENTS Sanders et a1. Feb. 17, 1953 Garrett Apr. 28, 1953 

